wont build past 50 psi and blows air out the intake

by Curtis
(Canada)

This just started and I replaced the pressure switch and check valve already.

the compressor runs fine until 50 psi and will run constant but blow air out the middle pump intake but the other two pumps suck in the air.

the pump is a triple piston pump with a 5hp motor any help would be awesome.

This setup is only a few months old.

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Bill says...

Hi Curtis. A compressor that runs and doesn't build air pressure past a certain point can have a number of issues. The one you point out is the one you have to fix first, and that is, the intake valve on that cylinder has failed.

I don't know if yours is a three stage, or just a three pump compressor (likely the latter) but for sure, rather than pumping air into the tank, the one cylinder is simply ingesting and blowing air right back out.

Time to tear down that pump and check the condition of the intake valve.

Cheers,

Bill